The present disclosure relates generally to synthesis of pentachlorophenol, and more particularly to method(s) for reducing microcontaminants during synthesis of pentachlorophenol.
Pentachlorophenol is a wood preservative generally manufactured via catalyzed chlorination of phenol or chlorophenol mixtures in the liquid phase. The process for synthesizing pentachlorophenol often results in the production of ppm levels of polychlorinated dibenzodioxins (PCDD) and polychlorinated dibenzofurans (PCDF) with six or more chlorine substituents.
Generally, such processes have a large increase in the toxic equivalent (TEQ) concentration during a narrow window in time near the maximum pentachlorophenol yield. Further, the TEQ concentration seems to increase further in the cooled and solidified post-reaction samples.
Reduction of the microcontaminant levels in the pentachlorophenol product is desirable for many reasons, and in particular, for environmental purposes. The toxins that may be produced during synthesis of the pentachlorophenol product may cause or increase the risk of undesirable environmental and health effects.
As such, it would be desirable to provide a method for synthesizing pentachlorophenol with substantially reduced amounts of microcontaminants.